Electric cable termination module having a gas-trap valve

ABSTRACT

An underground electric power cable termination module of a type having a load-break contact mounted therein is provided with a gas-trap valve that operates to prevent arc-generated gases from leaving the module when a contactor of a second module is separated from the load-break module. By thus trapping hot, ionized gases within the load-break module, the risk of a restrike between the separated contacts, or between one of the contacts and an electrical ground shield on one of the modules is substantially eliminated.

United States Patent {111 3,763,461 Kotski i [451 Oct. 2, 1973 [541 ELECTRIC CABLE TERMINATION 2,268,904 1/1942 Schallis 292/D1G. 65

MODULE HAVING A G VALVE 3,542,986 11/1970 Kotski 200/149 A Primary Examiner-Richard E. Moore Attorney-Francis X. Doyle et a1.

[57] ABSTRACT An underground electric power cable termination module of a type having a load-break contact mounted therein is provided with a gas-trap valve that operates to prevent arc-generated gases from leaving the module when a contactor ofa second module is separated from the load-break module. By thus trapping hot, ionized gases within the load-break module, the risk of a restrike between the separated contacts, or between one of the contacts and an electrical ground shield on one of the modules is substantially eliminated.

14 Claims, 7 Drawing Figures Patented Oct. 2, 1973 2 Sheets-Sheet 1 Patented Oct. 2, 1973 2 Sheets-Sheet 2 xxwxxxxxxxxwa ELECTRIC CABLE TERMINATION MODULE HAVING A GAS-TRAP. VALVE BACKGROUND OF THE INVENTION In the field of underground power distribution systems, it is generally well known to use elastomeric cable termination modules to connect various components of the system together. It is also known in the prior art to provide such modules with load-break means that make it possible to disconnect a pair of modules in a system that is energized, i.e. to effect such a disconnection under load conditions. An example of such a loadmake, load-break module is disclosed and claimed in US. Pat. No. 3,542,986-Kotski, which issued on Nov. 24, 1970 and is assigned to the assignee of the present invention.

In order to rapidly extinguish the arcs that are formed between the separated, relatively movable contacts of such prior art, load-make, load-break modules, some type of gas-evolving, arc-quenching material is ordinarily mounted in the modules adjacent the aredeveloping contacts thereof. In operation, these gasevolving materials respond to the heat of an arc to produce large volumes of gas that operate to quickly snuff the arc. Although these arc-snuffmg materials are effective for their intended purpose, it has been found that in the relatively confined environment of underground cable termination modules the production of large volumes of gas may cause undesirable consequcnces; at least when relatively high voltages and large currents are interrupted by the load-break, loadmake contacts of the modules. Specifically, it has been found that when large volumes of hot, ionized gases are produced within an underground cable termination module, responsive to the generation of an arc therein, there is some risk that these gases will be blown outof the module into contact with a ground-potential shield mounted on the outer surface of the module. Thus, there is a danger that the hot ionized gases may form a low resistance electrical path between the ground shield and one of the energized contacts of the separated cable modules. Of course, the formation of such a low resistance path might very well cause a fault current to flow from the energized line conductor to ground, thereby creating a destructive situation, as well as increasing the risk of injury to any operator that may be manually manipulating the module.

Moreover, because of a need to incorporate adequate spacing between potentially conducting parts of underground cable modules to prevent sparkover between such parts, it was necessary in prior art modules to construct them on a relatively large scale of dimensions. Consequently, such modules were quite expensive to manufacture, as well as being relatively cumbersome to handle during installation and subsequent operation. Accordingly, it would be desirable to provide some means that would enable the overall size of underground cable termination modules of the loadmake, load-break type to be significantly miniaturized in size.

Therefore, a primary object of the present invention is to provide an underground cable termination module 1 of the load-break type with means for controlling the escape of ionized gas from the module, thereby to avoid the above-mentioned risks and disadvantages.

Another object of the invention is to provide an electric cable termination module having a gas-trap valve that is operable to effectively seal a load-break contact mounted within the module from the ambient atmosphere immediately after a second, movable contact is withdrawn, past the valve, from the module.

A further object of the invention is to provide an efficient gas-trap valve means for an electric cable termination module that is rugged and dependable in operation, while being relatively inexpensive to manufacture.

Additional objects and advantages of the invention will be apparent to those skilled in the art from the description of the invention contained herein, taken in conjunction with the attached drawings.

SUMMARY OF THE INVENTION The inventiondisclosed and claimed herein relates to an electric connector termination module and more particularly to ionized gas control means for such a module of the load-break type. Pursuant to the invention, a gas-trap valve is incorporated within a loadbreak type termination module to control the discharge of ionized gases from the module immediately following a load-break operation thereof. In the preferred form of the invention disclosed herein, a gas-trap valve member is pivotally mounted in the bore of a rod and bore contact assembly. The valve member is springbiased to a closed position in which it effectively seals the bore and prevents gas from leaving the module through the bore passageway. In operation, the valve is moved to its open position by forcing a cooperating rod-type contact against it to cause it to pivot to one side of the bore, where it remains until the rod-type contact is withdrawn from the bore. Of course, if the rod-type contact is withdrawn under load conditions, an arc will be drawn between it and the contact mounted within the bore, thereby generating gases within the bore. As soon as the rod-type contact leaves the bore, the gas-trap valve member seals the bore and prevents the hot ionized gases from forming a low electrical resistance path between either contact and a ground potential shield mounted on the exterior sur face of the termination module.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevation view, partly in cross section, of an electrical conductor termination module embodying the gas-trap valve means of the invention, shown in operating relationship with a second cable termination module that is adapted to be separated from it under a load current conducting condition.

FIG. 2 is a side elevation view, in cross section, and in an enlarged scale, of one end of the load-break conductor termination module illustrated in FIG. 1. This cross-sectional view illustrates the gas-trap valve member of the invention in its closed position.

FIG. 3 is a top plan view, in cross section, taken along the plane 33 in FIG. 2, to illustrate the inner'surface of the valve member of the invention.

FIG. 4 is a side elevation view, partly in cross section, illustrating the gas-trap valve member of the invention in its open position, and showing it with respect to a rod member that is adapted to be moved into contact with an electrical contactor mounted in the bore of the conductor termination module housing the gas-trap valve member.

FIG. 5 is a perspective view of a valve seat member that forms a component part of the gas-trap valve shown in FIGS. 24l.

FIG. 6 is a perspective view of the generally discshaped valve member illustrated in FIGS. 2-4.

FIG. 7 is a perspective view of a spring that is used to bias the valve member illustrated in FIG. 6 to its closed position, as shown in FIG. 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring first to FIG. 1 of the drawings, there is shown an electrical conductor termination module 1 comprising an elongated insulating housing 2 that may be formed of any conventional insulating material that is well-known in the field of underground power distribution. However, in the preferred embodiment of the invention, the housing 2 is formed of peroxidecured elastomeric material similar to that disclosed in copending United States Patent Application Ser. No. 36,05 1 which was filed on May 11, I970 now U.S. Pat. No. 3,657,469, and is assigned to the assignee of the present invention. As is shown in FIG. 1, the module 1 has a frusto-conical outer surface portion 3 that is adapted to cooperate with a mating surface portion in a second cable termination module 4, in a manner well known in the underground electric power distribution field. The module 1 includes an electrical contact 5 in the form of a plurality of resilient, arcuately-shaped fingers mounted on an integral base portion 5'. It will be understood that the contact 5 may be of any suitable form, such as that shown, or similar to the type of contact illustrated in the above-mentioned U.S. Pat. No. 3,542,986. In addition to the contact 5, module 1 includes a metallic cylinder 6 and an elongated copper conductor 7, both of which are shown in phantom in FIG. 1. The cylinder 6 and conductor 7 are formed of copper and thus provide an electrical circuit between one end of the module 1 and the contact 5. Although it is not necessary to attain an understanding of the present invention, if desired, the details of one suitable form of conducting circuit of this nature may be obtained by reference to the type of circuit structure used in U.S. Pat. No. 3,542,986. For the purpose of understanding the present invention, it is only necessary to appreciate that the contact 5 is suitably mounted within the insulating housing 2 of module 1, so that it is in communication with a bore 8 that is formed by any suitable means in the module 1, extending from the first end 9 thereof a predetermined distance into the housing 2.

For the purpose of simplifying the description of the invention herein, reference is made simply to a bore 8, but it will be understood that any suitable means defining a passageway through the outer end 9 of housing 2 into the vicinity of the contact 5 will be suitable for the purpose of practicing the present invention. In order to support the contact 5 in operating position, it is mounted in an insulating cylindrically-shaped sleeve member 10 that is mounted within the bore 8 in a relatively slidable manner. In other words, the sleeve 10 is free to reciprocate within bore 8 to afford a load-make, load-break function, similar to that described in U.S. Pat. No. 3,542,986. In this embodiment of the invention, the sleeve 10 is formed of plastic resin impregnated Fiberglas that is wound in the form of a hollow cylinder. The contactS may be cemented to the inner walls of sleeve 10 or otherwise suitably fastened in fixed position with respect thereto. In addition, it should be noted that the walls of bore 8 may be separated from the sleeve 10 by a metal cylinder 6a that may form an integral extension of the larger diameter cylinder 6, as in the preferred form of the invention.

Pursuant to the present invention, a gas-trap valve 11 is mounted adjacent the outermost end 9 of the housing 2, in sleeve 10. The gas-trap valve 11 is shown in greater detail in FIGS. 2 and 4 of the drawing. A detailed description of gas-trap valve 11 will be given below, but at this point, it should be understood that valve 11 is effective, when moved to its closed position to substantially seal the end of sleeve 10, and thus bore 8. Valve 11 is further effective to permit entry of a movable contact, such as the contact 12 (shown in phantom) mounted in module 4, into the sleeve .10, and bore 8, when the valve is moved to its open position. Consequently, ionized gases formed by the creation of an are between the contact 5 and the contact 12, or any other contact that is positioned within the bore 8, is confined within the bore 8 by the valve 11.

Before making reference to FIG. 2, it should be noted that the conductor termination 4 includes a rod of gasevolving insulating material 13 that is mounted on the outer end of contact 12. The tip of this rod 13 is also shown in FIG. 4 of the drawing to facilitate a description of the operation of the gas-trap valve 11, below.

Now, referring to FIGS. 2, 3 and 4, a detailed description of the gas-trap valve 11 of the invention will be undertaken. The gas-trap valve 11 comprises a valve seat member 14 that is mounted in sleeve 10 adjacent the first end 9 of the housing 2 (see FIG. 1). Valve 11 also comprises a pivotally mounted valve member 15 that is operable to pivot between a closed position, such as that shown in FIG. 2 and an open position, such as that shown in FIG. 4. It will be appreciated that various different types of materials will be suitable to form the component parts of valve 11, but in the preferred form of the invention, both the valve seat member 14 and the pivotally mountedvalve member 15 are formed of a thermo-plastic dielectric material such as Nylon, Celcon or Delrin.

Valve member 15 is pivotally mounted on a hinge pin 16 that is mounted adjacent one side of the member 15, as shown in FIGS. 2-4. As best seen in FIG. 6 of the drawing, the valve member 15 includes means 17 and 17 that are formed to define at least one aperture 17a (and 17a) therethrough for receiving the pin 16, in the assembled position shown in FIGS. 2-4. The pin 16 is mounted in apertures 18 and 18a formed in the valve seat member 14, as shown in FIG. 5. In this embodiment of the invention the pin 16 is formed of steel and it is freely rotatable with respect to both the valve member 15 and the valve seat member 14. Of course, other suitable hinge means may be employed in alternative embodiments of the invention,

In order to exert a biasing force against the valve member 15 to continuously bias it to its closed position, a spring 19 (shown in detail in FIG. 7) is mounted around the pin 16 and between the valve member 15 and seat member 14, as shown in FIGS. 2-4. Obviously, various different spring means may be used to afford such a biasing function, but in the preferred embodiment of the invention the relatively short legs 20 and 20 (see FIG. 7) extending from one end of the spring, operating in combination with the short leg portion 21 extending from the other end of the spring, perform in a desirable manner to provide the necessary closing bias to the spring member 15. As is best shown in FIG.

. 2, the leg portion 20' does not engage the central portion of the valve member 15, until it is moved partially toward its open position. However, leg portions 20 and 20' are in continuous contact with the corner of the inner surface of valve member 15 so that a continuous closing bias is applied thereto. It will be appreciated that during assembly the spring 19 is placed under tension by biasing the legs 20 and 20' against valve member 15 and the leg 21 against the valve seat member 14, as shown in FIGS. 2 and 4.

An important aspect of the invention is the rate of closure of valve member 15. I have found that to provide optimum anti-arc, gas-sealing results, valve member 15 should move through 90, immediately following -removal of rod 13, within 2.5 milliseconds. Accordingly, the weight of valve member 15, the strength of spring 19, and the friction of the valve 11 should be adjusted to provide this optimum result. It will be understood that in some applications of the invention other closing speeds may be more suitable, but generally, best anti-arcing results are obtained when the valve member 15 is closed within at least 5 milliseconds after a rod contact, or contact follower, is moved past the valve through the aperture in valve seat 14.

In addition to providing a mount for the gas-trap valve II on its outer end, the sleeve has a piece of gas-evolving arc-extinguishing material 10a, in the form of a hollow cylinder, mounted within it. This gasevolving material is effective in response to an are being drawn across it, between the contacts 12 and 5, as discussed above, to liberate arc-snuffing gases. Any suitable material may be used to form the piece 10a, but in the preferred embodiment of the invention a gasevolving epoxy similar to that described in co-pending U.S. Patent Application, Ser. No. 764,677, filed Jan. 20, 1971 now U.S. Pat. No. 3,586,802, and assigned to the assignee of the present invention, is employed. However, a piece of Delrin, Celcon, molybdenum disulfide-loaded nylon or other gas-evolving dielectric material may be used in alternative embodiments of the invention to form a piece similar to piece 10a.

It will be noted that the valve seat member 14 is formed to define a generally annular lip portion 14a which has a slotted cylindrical portion 14b extending inwardly therefrom. These structural features are best seen in FIG. 5 of the drawing. As shown in FIGS. 2 and 4, the valve member 15 is pivotally mounted on the valve seat member 14 so that it fits into the slot 14b defined by the slotted cylindrical portion 14b when the valve member 15 is moved into its open position. It will be noted that the slotted cylindrical portion 14b of valve seat member 14 comprises a first section 140 having an outside diameter smaller than the inside diameter of the sleeve 10, and a second section 14d having an outside diameter larger than the diameter of the first section 14c so that a ridge is defined between these two sections 140-41, (as best seen in FIGS. 2, 4 and 5). In the preferred form of the invention disclosed herein, the outside diameter of the second section 14d is greater than the outside diameter of the sleeve 10, as shown. Thus, the ridge between sections l4c-d rests on the end of sleeve 10. This configuration has been found to be particularly desirable in assembling a collar member 22, which will now be described in detail.

Referring to FIGS. 2-4, it will be seen that a collar member 22 is mounted over the slot 14b (shown in FIG. 5) which is formed in the slotted cylindrical portion 14b of the valve seat member 14. Collar member 22 is formed of fiberglass, or any other suitable dielectric material. In its assembled position, it is sealed in substantially gas-tight relationship with the sleeve member III and the valve seat member 14 by being glued or otherwise suitably secured thereto, in order to prevent gas from escaping through the slot 14b in the valve seat member 14 into contact with the insulating housing 2. The collar member 22 is cylindrical in shape in the preferred embodiment of the invention and it is mounted substantially coaxially over the exterior surface of the sleeve 10 and the second cylindrical section 14d of seat member 14.

In addition to the slot 14b defined in the seat member 14, the sleeve 10 is provided with means defining a slot 10 therein. The slot 10' is in substantial alignment with the slot 14b in the valve seat member 14 when the component parts of valve 1 1 are in assembled position. This alignment allows the valve member 15 to be pivoted through both of the slots 10' and 14b into its open position, as shown in FIG. 4.

The collar member 22 comprises a generally cylindrical first section 22a (see FIG. 2) that has an inner diameter slightly larger than the outside diameter of the sleeve 10. Also, collar member 22 includes a second section 22b that has an inside diameter slightly larger than the outside diameter of the second section 14a of the slotted cylindrical portion 14b of valve seat member 14. This configuration of collar member 22 serves to define a substantially gas-tight pair of seals between the collar and, respectively, the sleeve 10 and valve seat member 14 when these component parts of the invention are in their assembled portions.

Finally, it should be noted that the pivotal valve member 15 is generally disc-shaped, as best seen in FIGS. 3 and 6, and the sealing surface 150 of valve memb er I5 is generally convex in configuration and protrudes outward from one side of the valve member. Of course, the sealing surface 15a is formed to seat tightly on the valve seat member 14 when the valve member 15 is in its closed position, thereby to form a substantially gas-tight seal between these two parts of valve 1 1. In addition to providing a strong construction and a good gas-tight sealing configuration, the convex sealing surface a provides an ideal, low friction surface against which the end of a rod-type contact, or bar of gas-evolving material 13 (see FIG. 4), may be forced, to pivot the valve member 15 into its open position.

In describing the operation of the invention it will first be assumed that the load-break module l is coupled in operating position with the module 4, shown in FIG. 1, thus, contact 5, and contact 12 would be engaged in conducting relationship. When the module 4 is manually separated from the module 11, an arc will be drawn between the contacts 5 and 12, if the circuit through the modules is energized. Such an arc will contact the gas-evolving materials of piece 22 and the arcfollowing rod 13 on contact 12, causing a large volume of arc-quenching gas to be evolved from these materials. Most of this gas is held within the sleeve 10 and bore 8 by the end of rod 13, as seen in FIG. 4. However, as the module 4 continues to move away from the module 1, rod 13 is withdrawn from the aperture in valve seat member 14. Since the valve member 15 is continuously biased toward its closed position, it is held in constant engagement with the rod 13 as rod 13 is withdrawn. Therefore, valve member 15 immediately seats on valve seat member 14 to substantially seal the sleeve 10 and bore 8, immediately following the complete withdrawal of rod 13. Thus, hot ionized gases that are generated by the above-mentioned are are trapped within the bore 8 so that they cannot form a low resistance path between either the contact 5 or contact 12 and the outer surface of module 14, which is normally provided with a conductive ground shield coating (not identified by number) in a manner well-known in the art. Accordingly, a primary object of the invention is satisfied.

It will be understood that following such an arcinterrupting operation the gas that is trapped within the bore 8 of module 1 will cool and thus be deionized, so that it does not pose a strikeover threat when a rodtype contact is subsequently inserted into the bore 8 of module 1, thereby again opening valve member 15. It should also be appreciated that in addition to its primary function of preventing an undesired fault condition from occurring between the contacts 5 and 12, and a ground shield on module 4, the gas-trap 11 serves to effectively seal the interior of sleeve 10, and bore 8 of module 1, from contamination by moisture or other undesirable contaminants that might otherwise fall into the aperture defined by valve seat member 14 when the module 1 is disconnected from a complementary module, such as module 4 described above.

It will be apparent to those skilled in the art that additional modifications and alternative embodiments of the invention disclosed above may be developed without departing from the teaching of the invention. Accordingly, it is my intention to define the true scope and spirit of the invention in the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical conductor termination module comprising an elongated insulating housing, means defining an elongated, generally cylindrical, contact-receiving bore that extends from a first end of said housing a predetermined distance into the housing, a first electrical contact mounted in said housing in communication with the inner end of said bore, a second manually movable contact formed to fit snugly within the outer end of said bore when moved into engagement with said first contact, said bore being effective to direct arc-generated gases developed by an are between said contacts toward the second contact thereby causing said gases to exert a force that tends to expel said sec- 0nd contact and said gases from said bore, a gas-trap valve mounted adjacent the outermost end of said bore, said valve being operable to move rapidly into a closed position thereby to effectively seal the outer end of the bore and trap arc-generated gases therein, responsive to the second contact being moved outward in said bore beyond the valve and being further operable to permit entry of said second contact into said bore when the valve is moved to its open position, said ionized gases directed against said second contact being effective to exert said force on the second contact until the gases are trapped within the bore by said valve being moved to its closed position.

2. An invention as claimed in claim I wherein said gas-trap valve comprises a valve seat member mounted adjacent said first end of the housing, and a pivotally mounted valve member that is operable to pivot between a closed position in which it is seated on the valve seat member and an open position in which it is moved to one side of said bore.

3. An invention as defined in claim 2 wherein said valve seat member includes a hinge pin, mounted adjacent one side thereof, and wherein said valve member includes means defining an aperture therethrough for receiving said pin therein, said valve member being operable to pivot around the longitudinal axis of said pin to move between its open and closed positions.

4. An electrical conductor termination module comprising an elongated insulating housing, means defining a contact-receiving bore that extends from a first end of said housing a predetermined distance into the housing, an electrical contact mounted in said housing in communication with said bore, an insulating sleeve mounted in said bore, a piece of gas-evolving, arcextinguishing material mounted in said sleeve adjacent said contact, said contact being adapted to be engaged by a second contact when moved into said sleeve, and a gas-trap valve mounted adjacent the outermost end of said sleeve, said valve comprising a valve seat member and a pivotally mounted valve member, said valve seat member being formed to define a generally annular lip portion having a slotted cylindrical portion extending inwardly therefrom, said valve member being pivotally mounted on the valve seat member so that it fits into the slot defined by said slotted cylindrical portion when the valve member is in its open position, said valve member being formed to define a sealing surface that seats on the valve seat member in substantially gastight relationship when the valve member is in its closed position.

5. An invention as defined in claim 4 including a spring mounted between said valve member and said valve seat member to exert a biasing force against the valve member, thereby to continuously bias it to its closed position with a force that is effective to move the valve member through an arc of within three milliseconds.

6. An invention as defined in claim 4 including a collar member mounted over the slot in said slotted cylindrical portion of the valve seat member in substantially gas-tight relationship with the sleeve member and the valve seat member, thereby to prevent gas from escaping through the slot in the seat member into contact with the insulating housing.

7. An invention as defined in claim 6 wherein said collar member is cylindrical in shape and is mounted coaxially over the exterior of said sleeve member and said slotted cylindrical portion of the valve seat member.

8. An invention as defined in claim 4 wherein said slotted cylindrical portion of said valve member comprises a first and a second section, said first section having an outside diameter smaller than the inside diameter of said sleeve, whereby the first section is slidably fitable into one end of the sleeve, said second section having an outside diameter larger than said first section, thereby to define a ridge between said sections.

9. An invention as defined in claim 8 wherein the outside diameter of said second section is greater than the outside diameter of said sleeve.

10. An invention as defined in claim 9 including means defining a slot in the outer end of said sleeve, said slot in the sleeve being in substantial alignment with the slot in said valve seat member, thereby to allow the valve member to be pivoted through both of said slots into its open position.

11. An invention as defined in claim 10 including a collar member mounted over the slot in said sleeve in substantially gas-tight relationship with the sleeve member and said valve seat member.

12. An invention as defined in claim 11 wherein said collar member comprises generally cylindrical first and second sections, said first collar section having an inner diameter slightly larger than the outside diameter of said sleeve and said second section of the collar member having an inside diameter slightly larger than the outside diameter of the second section of the slotted cylindrical portion of said valve seat member, thereby to define substantially gas-tight seals between the collar member and said sleeve and valve seat member when they are in their assembled positions.

13. An invention as defined in claim 4 wherein said valve member is generally disc-shaped and wherein said sealing surface is generally convex in configuration and protrudes from one side of said valve member.

14. The invention defined in claim 4 wherein said insulating housing member has an outer frusto-conical surface portion, the longitudinal axis of which is substantially concentric with the longitudinal axis of said bore, the small diameter end of said frusto-conical surface being adjacent the outermost end of said sleeve. 

1. An electrical conductor termination module comprising an elongated insulating housing, means defining an elongated, generally cylindrical, contact-receiving bore that extends from a first end of said housing a predetermined distance into the housing, a first electrical contact mounted in said housing in communication with the inner end of said bore, a second manually movable contact formed to fit snugly within the outer end of said bore when moved into engagement with said first contact, said bore being effective to direct arc-generated gases developed by an arc between said contacts toward the second contact thereby causing said gases to exert a force that tends to expel said second contact and said gases from said bore, a gas-trap valve mounted adjacent the outermost end of said bore, said valve being operable to move rapidly into a closed position thereby to effectively seal the outer end of the bore and trap arc-generated gases therein, responsive to the second contact being moved outward in said bore beyond the valve and being further operable to permit entry of said second contact into said bore when the valve is moved to its open position, said ionized gases directed against said second contact being effective to exert said force on the second contact until the gases are trapped within the bore by said valve being moved to its closed position.
 2. An invention as claimed in claim 1 wherein said gas-trap valve comprises a valve seat member mounted adjacent said first end of the housing, and a pivotally mounted valve member that is operable to pivot between a closed position in which it is seated on the valve seat member and an open position in which it is moved to one side of said bore.
 3. An invention as defined in claim 2 wherein said valve seat member includes a hinge pin, mounted adjacent one side thereof, and wherein said valve member includes means defining an aperture therethrough for receiving said pin therein, said valve member being operable to pivot around the longitudinal axis of said pin to move between its open and closed positions.
 4. An electrical conductor termination module comprising an elongated insulating housing, means defining a contact-receiving bore that extends from a first end of said housing a predetermined distance into the housing, an electrical contact mounted in said housing in communication with said bore, an insulating sleeve mounted in said bore, a piece of gas-evolving, arc-extinguishing material mounted in said sleeve adjacent said contact, said contact being adapted to be engaged by a second contact when moved into said sleeve, and a gas-trap valve mounted adjacent the outermost end of said sleeve, said valve comprising a valve seat member and a pivotally mounted valve member, said valve seat member being formed to define a generally annular lip portion having a slotted cylindrical portion extending inwardly therefrom, said valve member being pivotally mounted on the valve seat member so that it fits into the slot defined by said slotted cylindrical portion when the valve member is in its open position, said valve member being formed to define a sealing surface that seats on the valve seat member in substantially gas-tight relationship when the valve member is in its closed position.
 5. An invention as defined in claim 4 including a spring mounted between said valve member and said valve seat member to exert a biasing force against the valve member, thereby to continuously bias it to its closed position with a force that is effective to move the valve member through an arc of 90* within three milliseconds.
 6. An invention as defined in claim 4 including a collar member mounted over the slot in said slotted cylindrical portion of the valve seat member in substantially gas-tight relationship with the sleeve member and the valve seat member, thereby to prevent gas from escaping through the slot in thE seat member into contact with the insulating housing.
 7. An invention as defined in claim 6 wherein said collar member is cylindrical in shape and is mounted coaxially over the exterior of said sleeve member and said slotted cylindrical portion of the valve seat member.
 8. An invention as defined in claim 4 wherein said slotted cylindrical portion of said valve member comprises a first and a second section, said first section having an outside diameter smaller than the inside diameter of said sleeve, whereby the first section is slidably fitable into one end of the sleeve, said second section having an outside diameter larger than said first section, thereby to define a ridge between said sections.
 9. An invention as defined in claim 8 wherein the outside diameter of said second section is greater than the outside diameter of said sleeve.
 10. An invention as defined in claim 9 including means defining a slot in the outer end of said sleeve, said slot in the sleeve being in substantial alignment with the slot in said valve seat member, thereby to allow the valve member to be pivoted through both of said slots into its open position.
 11. An invention as defined in claim 10 including a collar member mounted over the slot in said sleeve in substantially gas-tight relationship with the sleeve member and said valve seat member.
 12. An invention as defined in claim 11 wherein said collar member comprises generally cylindrical first and second sections, said first collar section having an inner diameter slightly larger than the outside diameter of said sleeve and said second section of the collar member having an inside diameter slightly larger than the outside diameter of the second section of the slotted cylindrical portion of said valve seat member, thereby to define substantially gas-tight seals between the collar member and said sleeve and valve seat member when they are in their assembled positions.
 13. An invention as defined in claim 4 wherein said valve member is generally disc-shaped and wherein said sealing surface is generally convex in configuration and protrudes from one side of said valve member.
 14. The invention defined in claim 4 wherein said insulating housing member has an outer frusto-conical surface portion, the longitudinal axis of which is substantially concentric with the longitudinal axis of said bore, the small diameter end of said frusto-conical surface being adjacent the outermost end of said sleeve. 